Joseph W. Akin did serve as Surgeon in the 16th. Regiment, Miss. Infantry from June 12, 1861 until he resigned February 21, 1862. Here is a capsule history of this unit although he is not noted - http://www.mississippiscv.org/MS_Units/16th_MS_INF.htm
I know there are 93 cards in this military service record which includes several letters written by J. W. Akin, these should prove helpful to answering your questions.
J.W. Aiken (First_Last)
Regiment Name General and Staff Officers, Corps, Division and Brigade Staffs, Non-com. Staffs and Bands, Enlisted Men, Staff Departments, C.S.A.
Side Confederate
Company
Soldier's Rank_In Surgeon
Soldier's Rank_Out Surgeon
Alternate Name J.W./Akin
Notes
Film Number M818 roll 1
These records and any available for his service in the 16th. Miss. Regiment may be procured from this site:
http://history-sites.com/research/index.html